1. Field of the Invention
The invention relates to volume rendering. More particularly, it relates to a method for rendering volume data as texture maps on top of polyhedral surfaces.
2. Prior Art
Visualization of large volumetric datasets frequently requires the selection of subsets in order to discard unnecessary or obstructing information. Volume rendering offers two ways of selecting: one is to choose the opacity mapping functions appropriately, and the other is to use clipping planes. These two methods, however, are not always sufficient. For example, if the region of interest (ROI) to be rendered is embedded inside data of similar features, and its shape is not convex, it cannot easily be isolated by using clipping planes.
Surface shaded display (SSD) or surface shaded volume rendering are other methods that are used for volume rendering. SSD generally requires 3D texture acceleration hardware that is only available on very expensive machines.
Another alternative for image evaluation is segmentation. Segmentation is a division of the complex picture into parts corresponding to regions or object. For data sets that have a low signal to noise ratio, or for embedded ROIs, segmentation is not always an applicable alternative. Binary segmented surfaces also lack information that is available in the volume dataset.